| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package ndexec |
| 4 | |
| 5 | import ( |
| 6 | "bytes" |
| 7 | "context" |
| 8 | "errors" |
| 9 | "fmt" |
| 10 | "os" |
| 11 | "os/exec" |
| 12 | "path/filepath" |
| 13 | "runtime" |
| 14 | "strings" |
| 15 | "time" |
| 16 | |
| 17 | "github.com/netdata/netdata/go/plugins/logger" |
| 18 | "github.com/netdata/netdata/go/plugins/pkg/buildinfo" |
| 19 | ) |
| 20 | |
| 21 | const stderrLimit = 8 << 10 // 8 KiB |
| 22 | |
| 23 | // Runner holds helper paths for execution. |
| 24 | type runner struct { |
| 25 | ndRunPath string |
| 26 | ndSudoPath string |
| 27 | } |
| 28 | |
| 29 | func newRunnerFromBuildinfo() *runner { |
| 30 | var sfx string |
| 31 | if runtime.GOOS == "windows" { |
| 32 | sfx = ".exe" |
| 33 | } |
| 34 | return &runner{ |
| 35 | ndRunPath: filepath.Join(buildinfo.NetdataBinDir, "nd-run"+sfx), |
| 36 | ndSudoPath: filepath.Join(buildinfo.PluginsDir, "ndsudo"+sfx), |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | var defaultRunner = newRunnerFromBuildinfo() |
| 41 | |
| 42 | // RunUnprivileged runs binPath via nd-run with a timeout. |
| 43 | // Returns stdout. On error, wraps the original error and includes a trimmed stderr snippet. |
| 44 | func RunUnprivileged(log *logger.Logger, timeout time.Duration, binPath string, args ...string) ([]byte, error) { |
| 45 | out, _, err := RunUnprivilegedWithCmd(log, timeout, binPath, args...) |
| 46 | return out, err |
| 47 | } |
| 48 | |
| 49 | // RunNDSudo runs cmd via ndsudo with a timeout. |
| 50 | // Returns stdout. On error, wraps the original error and includes a trimmed stderr snippet |
| 51 | func RunNDSudo(log *logger.Logger, timeout time.Duration, cmd string, args ...string) ([]byte, error) { |
| 52 | out, _, err := RunNDSudoWithCmd(log, timeout, cmd, args...) |
| 53 | return out, err |
| 54 | } |
| 55 | |
| 56 | // RunUnprivilegedWithCmd runs binPath via nd-run and also returns the formatted command string. |
| 57 | func RunUnprivilegedWithCmd(log *logger.Logger, timeout time.Duration, binPath string, args ...string) ([]byte, string, error) { |
| 58 | argv := append([]string{binPath}, args...) |
| 59 | out, cmd, _, err := defaultRunner.run(log, timeout, "", defaultRunner.ndRunPath, "RunUnprivileged", nil, argv...) |
| 60 | return out, cmd, err |
| 61 | } |
| 62 | |
| 63 | // RunNDSudoWithCmd runs cmd via ndsudo and also returns the formatted command string. |
| 64 | func RunNDSudoWithCmd(log *logger.Logger, timeout time.Duration, cmd string, args ...string) ([]byte, string, error) { |
| 65 | argv := append([]string{cmd}, args...) |
| 66 | out, formatted, _, err := defaultRunner.run(log, timeout, "", defaultRunner.ndSudoPath, "RunNDSudo", nil, argv...) |
| 67 | return out, formatted, err |
| 68 | } |
| 69 | |
| 70 | // RunUnprivilegedWithEnv runs binPath via nd-run with a custom environment. |
| 71 | func RunUnprivilegedWithEnv(log *logger.Logger, timeout time.Duration, env []string, binPath string, args ...string) ([]byte, error) { |
| 72 | out, _, err := RunUnprivilegedWithEnvCmd(log, timeout, env, binPath, args...) |
| 73 | return out, err |
| 74 | } |
| 75 | |
| 76 | // RunUnprivilegedWithEnvCmd runs binPath via nd-run with a custom environment and returns the formatted command string. |
| 77 | func RunUnprivilegedWithEnvCmd(log *logger.Logger, timeout time.Duration, env []string, binPath string, args ...string) ([]byte, string, error) { |
| 78 | argv := append([]string{binPath}, args...) |
| 79 | out, cmd, _, err := defaultRunner.run(log, timeout, "", defaultRunner.ndRunPath, "RunUnprivileged", env, argv...) |
| 80 | return out, cmd, err |
| 81 | } |
| 82 | |
| 83 | // RunOptions configure nd-run/ndsudo execution helpers. |
| 84 | type RunOptions struct { |
| 85 | Env []string |
| 86 | Dir string |
| 87 | } |
| 88 | |
| 89 | // RunUnprivilegedWithOptions runs binPath via nd-run honoring the provided options. |
| 90 | func RunUnprivilegedWithOptions(log *logger.Logger, timeout time.Duration, opts RunOptions, binPath string, args ...string) ([]byte, error) { |
| 91 | out, _, err := RunUnprivilegedWithOptionsCmd(log, timeout, opts, binPath, args...) |
| 92 | return out, err |
| 93 | } |
| 94 | |
| 95 | // RunUnprivilegedWithOptionsCmd is RunUnprivilegedWithOptions plus the formatted command string. |
| 96 | func RunUnprivilegedWithOptionsCmd(log *logger.Logger, timeout time.Duration, opts RunOptions, binPath string, args ...string) ([]byte, string, error) { |
| 97 | argv := append([]string{binPath}, args...) |
| 98 | out, cmd, _, err := defaultRunner.run(log, timeout, opts.Dir, defaultRunner.ndRunPath, "RunUnprivileged", opts.Env, argv...) |
| 99 | return out, cmd, err |
| 100 | } |
| 101 | |
| 102 | // RunUnprivilegedWithOptionsUsage runs binPath via nd-run and returns stdout, formatted command, resource usage and error. |
| 103 | func RunUnprivilegedWithOptionsUsage(log *logger.Logger, timeout time.Duration, opts RunOptions, binPath string, args ...string) ([]byte, string, ResourceUsage, error) { |
| 104 | argv := append([]string{binPath}, args...) |
| 105 | return defaultRunner.run(log, timeout, opts.Dir, defaultRunner.ndRunPath, "RunUnprivileged", opts.Env, argv...) |
| 106 | } |
| 107 | |
| 108 | // RunUnprivilegedWithOptionsUsageContext runs binPath via nd-run using the caller |
| 109 | // context as the ownership boundary for cancellation and stop/reload propagation. |
| 110 | func RunUnprivilegedWithOptionsUsageContext( |
| 111 | ctx context.Context, |
| 112 | log *logger.Logger, |
| 113 | timeout time.Duration, |
| 114 | opts RunOptions, |
| 115 | binPath string, |
| 116 | args ...string, |
| 117 | ) ([]byte, string, ResourceUsage, error) { |
| 118 | argv := append([]string{binPath}, args...) |
| 119 | return defaultRunner.runContext(ctx, log, timeout, opts.Dir, defaultRunner.ndRunPath, "RunUnprivileged", opts.Env, argv...) |
| 120 | } |
| 121 | |
| 122 | // SetRunnerPathsForTests overrides the nd-run and ndsudo helper paths. |
| 123 | // It is intended for test environments that need to stub the helpers. |
| 124 | func SetRunnerPathsForTests(ndRunPath, ndSudoPath string) { |
| 125 | if ndRunPath != "" { |
| 126 | defaultRunner.ndRunPath = ndRunPath |
| 127 | } |
| 128 | if ndSudoPath != "" { |
| 129 | defaultRunner.ndSudoPath = ndSudoPath |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | // RunDirect runs binPath directly with a timeout, without any wrapper (nd-run/ndsudo). |
| 134 | // Returns stdout. On error, includes the command string and a trimmed stderr snippet. |
| 135 | func RunDirect(log *logger.Logger, timeout time.Duration, binPath string, args ...string) ([]byte, error) { |
| 136 | out, cmd, _, err := RunDirectWithOptionsUsageContext(context.Background(), log, timeout, RunOptions{}, binPath, args...) |
| 137 | if err != nil { |
| 138 | return out, fmt.Errorf("'%s' execution failed: %w", cmd, err) |
| 139 | } |
| 140 | return out, nil |
| 141 | } |
| 142 | |
| 143 | // RunDirectWithOptionsUsageContext runs binPath directly using the caller context |
| 144 | // while honoring the provided environment and working-directory options. |
| 145 | func RunDirectWithOptionsUsageContext( |
| 146 | ctx context.Context, |
| 147 | log *logger.Logger, |
| 148 | timeout time.Duration, |
| 149 | opts RunOptions, |
| 150 | binPath string, |
| 151 | args ...string, |
| 152 | ) ([]byte, string, ResourceUsage, error) { |
| 153 | return defaultRunner.runContext(ctx, log, timeout, opts.Dir, binPath, "RunDirect", opts.Env, args...) |
| 154 | } |
| 155 | |
| 156 | // FindBinary searches for a binary by trying names in PATH first, |
| 157 | // then checking defaultPaths on the filesystem. |
| 158 | // Returns the first found path, or an error if not found. |
| 159 | func FindBinary(names []string, defaultPaths []string) (string, error) { |
| 160 | for _, name := range names { |
| 161 | if path, err := exec.LookPath(name); err == nil { |
| 162 | return path, nil |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | for _, path := range defaultPaths { |
| 167 | if fi, err := os.Stat(path); err == nil && !fi.IsDir() { |
| 168 | return path, nil |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | if len(names) == 0 { |
| 173 | return "", fmt.Errorf("executable not found in default locations") |
| 174 | } |
| 175 | return "", fmt.Errorf("executable not found in PATH (%s) or default locations", strings.Join(names, ", ")) |
| 176 | } |
| 177 | |
| 178 | func (r *runner) run(log *logger.Logger, timeout time.Duration, dir string, helperPath, label string, env []string, argv ...string) ([]byte, string, ResourceUsage, error) { |
| 179 | return r.runContext(context.Background(), log, timeout, dir, helperPath, label, env, argv...) |
| 180 | } |
| 181 | |
| 182 | func (r *runner) runContext( |
| 183 | ctx context.Context, |
| 184 | log *logger.Logger, |
| 185 | timeout time.Duration, |
| 186 | dir string, |
| 187 | helperPath, label string, |
| 188 | env []string, |
| 189 | argv ...string, |
| 190 | ) ([]byte, string, ResourceUsage, error) { |
| 191 | if ctx == nil { |
| 192 | ctx = context.Background() |
| 193 | } |
| 194 | if timeout > 0 { |
| 195 | var cancel context.CancelFunc |
| 196 | ctx, cancel = context.WithTimeout(ctx, timeout) |
| 197 | defer cancel() |
| 198 | } |
| 199 | |
| 200 | ex := exec.CommandContext(ctx, helperPath, argv...) // argv comes from trusted sources; no shell, args passed separately |
| 201 | configureCommandCancellation(ex) |
| 202 | if dir != "" { |
| 203 | ex.Dir = dir |
| 204 | } |
| 205 | if len(env) > 0 { |
| 206 | ex.Env = env |
| 207 | } |
| 208 | |
| 209 | if log != nil { |
| 210 | log.Debugf("executing: %v", ex) |
| 211 | } |
| 212 | |
| 213 | var stderr bytes.Buffer |
| 214 | ex.Stderr = &stderr |
| 215 | |
| 216 | cmdStr := ex.String() |
| 217 | |
| 218 | out, err := ex.Output() |
| 219 | usage := extractUsage(ex.ProcessState) |
| 220 | if err != nil { |
| 221 | s := stderr.String() |
| 222 | if len(s) > stderrLimit { |
| 223 | s = s[:stderrLimit] + "… (truncated)" |
| 224 | } |
| 225 | // Normalize context-related errors so callers can distinguish the |
| 226 | // execution timeout cause from caller-owned cancellation. |
| 227 | if ctx.Err() != nil { |
| 228 | cause := context.Cause(ctx) |
| 229 | if cause != nil && !errors.Is(cause, ctx.Err()) { |
| 230 | err = cause |
| 231 | } else { |
| 232 | err = ctx.Err() |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | return out, cmdStr, usage, fmt.Errorf("%s: %v: %w (stderr: %s)", label, ex, err, strings.TrimSpace(s)) |
| 237 | } |
| 238 | |
| 239 | return out, cmdStr, usage, nil |
| 240 | } |